Received mine and while it´s still in breaking-in period (48h for now) the results are very promising and possitive.
I completely agree with Corley, for this task (Dac+integrated amp), this approach and implementation is very smart and the results are quite remarkable. The amp is VERY powerful and capable, it drives even difficult headhpones like my AKG K701 on the go with an astonishing ease but with headphones like AKG Y50 this dac really excels offering huge amounts of deep, controlled bass with detailed and transparent highs without any harshness.
Perhaps the only complaint to mention is that I would have preferred that the USB plug had been directly soldered to the board like all the others similar DACs. The integrated usb cable seems to be quite standard (WBT silver soldering? surely not...) instead of a direct, soldered connection perhaps would help even more to get a more quality sound removing the cord.
I'll compare the Asynchronous 9018 and this one, the Adaptive 9018. I find the Adaptive model is a little more efficient with its amp and more dynamic in the balance between bass and treble at the expense of accuracy. The Async model is still better, but it depends on the purpose. I use the Async as a desktop converter mostly, since I then Amp it separately with a hybrid valve setup. Where this model shines for me is being able to drive my 600 OHM Beyer T1 headphones really well by itself. They can both do it, but the extra dynamic power from this model allows volume, dynamics, deep bass, crystal clear transparency and silky smooth trebles without needing anything else but my phone and this converter. I think the Async model has a more accurate soundstage, I think of the Adaptive as fun and energetic. They are both miles above the excellent 9023 models. There seems to be a logical problem with it sometimes dropping out every few seconds until you stop and start it again, then it's ok.
Really good product ! The sound is really clear with good details. I have the Sabre ES9023 too, but I didn't take the time to make a real side/side comparison since the ES9023 is in my car 'home made' installation... But this 9018 sounds to be a great update ! Works well with Linux, and Android Nexus 7 (2013 model - Marshmallow CyanogenMod based)...